Verification of the oxygen consumption rate of the remaining coal in the gob by research and experiment

Abstract

ABSTRACTOxygen consumption rate is an important index to evaluate the oxidation performance of coal, and it usually has an exponential relationship with temperature. However, during the temperature-rising oxidation experiment, it was found that as the temperature increased, the oxygen concentration at the outlet of the reaction tank would gradually decrease to a certain value, which caused the oxygen consumption rate to gradually approach a certain constant and thus be unable to accurately express the oxygen consumption characteristics of coal. To solve this problem, we introduce a new parameter and propose a new calculation model. We conducted low-temperature oxidation experiments on coal samples from Yang Chang Wan Mine (YCW) and An Ze (AZ) Mines under different oxygen concentrations and different gas flow conditions. Experimental results show that the new model has an exponential relationship with temperature for the same coal sample. This relationship depends on the inherent properties of the coal and is independent of the oxygen concentration and flow rate. Through exponential fitting, the determination coefficients of the new models for the two coal samples under different oxygen concentrations are increased by 7.55% and 3.55%, respectively, compared with the old model; under different flow conditions, the coefficients of determination are increased by 2.93% and 6.08%, respectively. These results indicate that the new model can more accurately express the oxidation characteristics of coal compared to the old model, providing a more accurate theoretical basis for future studies on the spontaneous combustion of coal.